Rare species of lichen genus Usnea Dill. ex Adans of Ritsa relict national park (Abkhazia)

The article is concerned with study of lichens growing on the territory of Abkhasia. In the course of the practical research, 14 species of lichens from the genus Usnea were identified on the territory of Ritsa Relict National Park. Five species are new to Abkhazia, eleven species are new for the Ritsa Relict National Park. A key for their determination, as well as morphological and anatomical, chemotaxonomical features are presented.